Crap power out of my new turbo

[Dazz0i]

no, because the pressure that is going into the engine is measured on the intercooler hot-pipe, which is after the turbo.... increasing the size of it doesn't increase the volume of anything...


that's like saying.... 34psi in a 14" tyre isn't the same pressure as 34psi in an 18"... when,... it is... pressure is pressure... doesn't matter on the volumetrics of it. It takes more air to make that pressure, but in the turbo making pressure sense, that air is still moving at exactly the same size doesn't matter what size the turbo is.... a T51R makin' 18psi would still be exactly the same pressure, it'd just be less effort for it. And.... extremely laggy!

 

[manna_s15]

what dyno was it on and do you have the print out because the 3071 @18psi is pushing between 30-33 lb of air a min so is making about 330bhp@fly which sounds right so 270ish atw is about right

was it a dyno dynamics ??? if so post the graphs up im used t working with these machines

yeah it is dyno dynamics. link to the dyno graph is attached.
http://i117.photobucket.com/albums/o41/manna_85photos/DSC01595.jpg

 

[j@garagemac]

no, because the pressure that is going into the engine is measured on the intercooler hot-pipe, which is after the turbo.... increasing the size of it doesn't increase the volume of anything...


that's like saying.... 34psi in a 14" tyre isn't the same pressure as 34psi in an 18"... when,... it is... pressure is pressure... doesn't matter on the volumetrics of it. It takes more air to make that pressure, but in the turbo making pressure sense, that air is still moving at exactly the same size doesn't matter what size the turbo is.... a T51R makin' 18psi would still be exactly the same pressure, it'd just be less effort for it. And.... extremely laggy!

No the preasure is the same but the volume of air is greater and more air / more feul / more power its the basics of engine knowledge .
mate i build and tune cars for a living

ok so explain to me why our drift car at 1.1bar on the stock t28 made 297bhp atf
and after fitting the 2871r with z32 maf and 740cc injectors
at 1.1bar it made 360bhp atf and 360lb/ft but it was the same preasure
the 2871 flows more air so with the supporting mods more power .

 

[j@garagemac]

yeah it is dyno dynamics. link to the dyno graph is attached.
http://i117.photobucket.com/albums/o41/manna_85photos/DSC01595.jpg

fella why did they run it in 5th gear should of been done in 3rd or 4th makes no differnce 3-4 but 5th the run will take to long and generate to much heat on the dyno pull

so thats were some power may have gone its still there but wrong dyno conditions . do they have a proper dyno cell ?? as that makes big deffernce .

and your at and it are a fair bit apart also

 

[manna_s15]

hmmm u think the turbo is not suited for an s15? would u recommend perhaps swapping to a 2871r or gt2540? the thing is theres a few people running this turbo and making good figures. but maybe they have something i dont.

 

[j@garagemac]

what supporting mods do you have i.e fmic exhaust
and what brands ??
but it could be the tune on the ecu ??

also try getting the car dyno'd on another dd machine to get a like for like comparisson

rather than blame parts at this stage it helps to have second seperate dyno reading

kind regards jamie@garagemac

 

[j@garagemac]

also do you have the boost and afr dyno sheet

afr in lambda please :thumbs:

kind regards jamie@garagemac

 

[manna_s15]

what supporting mods do you have i.e fmic exhaust
and what brands ??
but it could be the tune on the ecu ??

also try getting the car dyno'd on another dd machine to get a like for like comparisson

rather than blame parts at this stage it helps to have second seperate dyno reading

kind regards jamie@garagemac

supporting mods are:
FMIC greddy vspl
740cc nismo inj
power fc
tomei z32 afm
splitfire coilpacks
greddy profec b ebc
nismo fuel pump

i didnt get afr sheet.
hey really appreciate the help jamie. hope i can find the prob dont wanna resort to sellin her.....

 

[j@garagemac]

i hope we sort it to mate as its bad when a little poblem ends up in a car sold .

the afr sheet is quit important as it could be down to the feuling ? running rich or lean either way will affect the power output

but all the parts should support the turbo very well usually problems like this happen when people buy $50 intercoolers off ebay etc and they act like big restrictors on the car . when tuning you get what you pay for .

Are you friedly with your tuner ?? if so i print out of the afr and boost isn't hard to retrive from the computer .
did your dyno centre map the car ??

 

[Dazz0i]

No the preasure is the same but the volume of air is greater and more air / more feul / more power its the basics of engine knowledge .
mate i build and tune cars for a living

ok so explain to me why our drift car at 1.1bar on the stock t28 made 297bhp atf
and after fitting the 2871r with z32 maf and 740cc injectors
at 1.1bar it made 360bhp atf and 360lb/ft but it was the same preasure
the 2871 flows more air so with the supporting mods more power .

i agree, the turbo can takes more air to fill because it's a bigger space, but, the intercooler and piping, which is where the boost pressure is measured. so is the block that it's going into.... the turbo is only the compressor. maybe the turbo on you drift car was on it's peak/running un-efficiently and capped by the stock AFM, hence the increase in power?

 

[j@garagemac]

but, boost is limited on S15's from the throttle side of the turbo.... so going on a 15% increase in size on exhaust side. doesn't mean an increase in power .....

the efficency of the turbo may well be more suit or not, which will change the power delivery and feel...

so how does the s15 limit the boost on the throttle side ???????
im intreaged not trying to argue for the sake of it but it just dont make sence ???

 

[Dazz0i]

because, boost is limited by the actuator/wastegate on the S15.... that is controlled by the solenoid/boostcontroller, which... gets it's pressure reading from the hotpipe of the intercooler.... so...

the boost pressure is measured after the turbo has done it's job of compressing the air.

the turbo is only the compressor, just because it's bigger doesn't mean it "is" flowing more air... it's just capable of flowing more.

18psi is 18psi.... there's just no other way about it.... there is no extra air going into the block. like i said, i could run a T51R but it doesn't mean my peak power/boost would change just cause the turbo is bigger.... it just means i'd be capable of pushing alot more boost if i wanted to...

 

[j@garagemac]

ffs it is flowing more air as its bigger you obviously have no idea what your talking about now as hance why a t28 at 18psi is flowing 28lb of air a min

and a 3071r is flowing 33-35lb of air a min so its flowing more air period

 

[manna_s15]

i hope we sort it to mate as its bad when a little poblem ends up in a car sold .

the afr sheet is quit important as it could be down to the feuling ? running rich or lean either way will affect the power output

but all the parts should support the turbo very well usually problems like this happen when people buy $50 intercoolers off ebay etc and they act like big restrictors on the car . when tuning you get what you pay for .

Are you friedly with your tuner ?? if so i print out of the afr and boost isn't hard to retrive from the computer .
did your dyno centre map the car ??

well my tuner to me is just a tuner. dont really deal with him just with the owner of the workshop. althought the tuner has a very good rep. will take it to another workshop and ill ask for the afr and boost printouts. that is if he doesnt find the prob. i was going to take out everything when i sell the car probably, return to stock.

 

[j@garagemac]

it would be a shame to sell because of a little problem like this to be honost looking at the compressor map for that turbo its making the power it should at that boost preasure

 

[manna_s15]

tell me bout it! this is like my baby. i still got 3k rims coming from jap. someone did tell me that at 18psi its only hitting the start of the turbos peak efficiency. u think a manifold, and stage 1 cams will make a massive diff?

 

[TriniGT]

I would definitely look into getting some cams. Power is always limited by the weakest link, form your list I am not seeing any head work, springs retainers cams more importantly and some cam gears. Timing should also be checked and if tuned properly you should get the power you are looking for. Doublecheck things like your plugs and gapping, timing, boost leaks, also overkill on the size of intercooler piping like having a 3" setup can make for a laggier setup but should not hinder the ulimate power. I would recommend a cam upgrade with some cam gears but with a stock turbo the power you have is more than doable.

 

[Dazz0i]

after a quick call to "turbo technics" cause i figured maybe you'd listen to the people that actually build turbos.....

i asked "if the a stock turbo was a T28 and a changed it to a T30, and was running 18psi, would the amount of air being flowed at 18psi be any different?"

his response was "no, the T30 would just be in the lower stages of it's capabilities."

if you'd like to call and comfirm this information youself.... please do.... 01604 705050

 

[j@garagemac]

how many 600+ bhp cars have you built i have looked at the compressor map for both turbos and a 3071r at 18psi is flowing more air period

end of, **** the boost valve etc it is a bigger turbo and flows more air
than a t28

so how come at 18psi a t28 will do between 280-300atf

and a 2871r at 18psi will do between 330-360 atf

mate you should open a tuning shop lol im trying to be constructive not rude on these threads but its like talking to a
wall
i use garret direct mate
i aree that it is in a lower state of its capability but it is still flowing more air

 

[Paul D]

Just my 2p's worth but if the inlet manifold was at 18psi with both turbo's wouldn't the power just be the same?

The way i look at it the t28 would be at its limit whilst the other one has the capability of pushing the manifold pressure higher hence more power.